1. Field of the Invention
The present invention relates to guiding devices of an elevator, which guide a car thereof to be traveled.
2. Description of the Related Art
In recent years, elevators have been made to travel at higher speed toward ultrahigh speed, as higher buildings have been constructed as skyscrapers. However, when an elevator travels at ultrahigh speed, it is influenced by the speed of wind in a hoistway, vibration of a main rope, and variable loads such as its compensating rope and a tail cord, etc., and vibration of a car is caused. This has a great influence on the riding comfort of the elevator which is one of the functions thereof.
Thus, in order to improve the riding comfort, some elevator machines have been proposed.
In a proposed elevator machine, on a car side, contact type of guiding devices and non-contact type of guiding devices are provided, the contact type of guiding device guiding a car while contacting guide rails at all times, the non-contact type of guiding devices having electromagnets which guide the car while being located opposite to the guide rails such that they are in non-contact with the guide rails. The magnetic forces from the electromagnets are varied to restrict lateral vibration applied to the car, thereby improving the riding comfort. This technique is disclosed in, e.g., Japanese patent No. 2616527.
In another proposed elevator machine, on a car side, electromagnets are provided such that each of them is in non-contact with a guide rail from three directions, and lateral vibration of a car at a regular operation time is detected. If the lateral vibration is great, a control instruction is corrected to reduce the lateral vibration. At a subsequent operation time of the elevator, the electromagnets are controlled by using the corrected control instruction, thereby restricting the lateral vibration of the elevator. This technique is disclosed in, e.g., Jpn. Pat. Appln. KOKAI Publication No. 5-178562.
A further proposed elevator machine is a car-stabilizing machine for stabilizing the riding comfort of a car. The stabilizing machine detects the acceleration of the car in the horizontal direction, and controls actuators based on the detected acceleration, thereby restricting horizontal variation of the car. This technique is disclosed in, e.g., Japanese patent No. 2889404.
Therefore, the above elevator machines can be achieved such that they are relatively light and compact, as in general guiding devices which guide a car while their rollers are in contact with guide rails at all times.
However, such contact type of guiding devices as disclosed in Japanese patent No. 2616527 are intended to restrict lateral vibration applied to a car, while contacting guide rails at all time. They are also influenced by dynamic deformation of the guide rails which is caused by warping of the guide rails and partial loads, etc. generating when the elevator travels.
Further, such a machine as disclosed in Jpn. Pat. Appln. KOKAI Publication No. 5-178562 detects lateral vibration of a car at a regular operation time, corrects a control instruction based on the detected value, and applies it to a subsequent operation, as a result of which it is prevented from being influenced by guide rails not regularly set. However, it cannot be prevented from being influenced by dynamic deformation of the guide rails which is caused by partial loads, etc. when the elevator travels while its traveling state varies momently.
Furthermore, such a machine as disclosed in Japanese patent No. 2889404 is formed to detect lateral vibration of a car, and perform a feedback control on actuators. In this machine, great forces for controlling vibration must be generated from the actuators, since the object to be controlled in vibration by the machine is the entire car. Accordingly, the machine cannot be expected to sufficiently control vibration.
In addition, it can be considered that warps in guide rails are stored in advance, and a feedforward control is carried out on an estimation-preceding basis based on the traveling position of the car. However, such a method cannot be expected to sufficiently control vibration, since dynamic deformation of the guide rails, which is caused by partial loads when the elevator travels, also occurs.